The present invention relates to a bass reflex type speaker system. More particularly, the invention relates to a bass reflex type speaker system in which the sound reproduction level at a mid frequency range is improved.
FIG. 1 shows a fragmentary cross sectional view of a well known prior art bass reflex type speaker system. In FIG. 1, a duct 2 is mounted on a baffle plate 1 of a cabinet 3 to permit the inside of the cabinet 3 to communicate with the outside thereof. The duct 2 also turns the back pressure of a diaphragm to direct it to the outside of the cabinet 3. A simple circuit hollow cylinder has been used as the duct 2 for the bass reflex type speaker system.
With a bass reflex type speaker system such as that described above, there has been a problem that sound in the mid frequency range leaks from an aperture of the duct 2 to cause an extreme peak (shown in FIG. 2) in the mid frequency response. FIG. 3, which is a frequency characteristic diagram of sound level at a duct aperture of a duct according to the prior art, provides a further view of a peak in sound level at frequency f.sub.p. Thus, articulateness in sound quality of the entire sound is lost.